An expander flange is a type of flange that is used to connect two pipes or vessels. It is designed to allow for the expansion and contraction of the pipes or vessels without causing damage. Expander flanges are typically made of stainless steel or carbon steel, and they can be either welded or bolted. Here are some of the technical specifications of expander flanges: Pressure rating: Expander flanges are available in a variety of pressure ratings, from 100 psi to 10,000 psi. Temperature rating: Expander flanges are available in a variety of temperature ratings, from -200 degrees Fahrenheit to 1200 degrees Fahrenheit. Material: Expander flanges are typically made of stainless steel or carbon steel. Finish: Expander flanges can be either bare or have a protective coating, such as a paint or plating. Size: Expander flanges are available in a variety of sizes, from 1/2 inch to 24 inches.